The present invention relates to a method for managing a cache of a user terminal connected to a network, and more particularly, to a method for managing a cache of a user terminal connected to a network, wherein information is rapidly displayed on a screen by storing more useful data in the cache.
In general, when a user uses a web browser to download a web page from a network such as the Internet to a user terminal, downloaded data is stored in a cache. The cache is a predetermined portion of the memory of the user terminal. Thus, when the web page later needs to be displayed again, it can be rapidly provided from the cache without having to be re-downloaded from the network.
FIG. 1A is an example of data downloaded from a network by a user, after the data has been processed in order to be displayed on the screen of the user terminal. In this example, the user downloads data of a xe2x80x98sportsxe2x80x99 web page, which is processed to obtain sports display data 110 composed of cache pages A1, A2 and A3. Then, the sports display data 110 is used to display the xe2x80x98sportsxe2x80x99 web page on the screen. Next, the user downloads data of a xe2x80x98rugbyxe2x80x99 web page, via a hyperlink in the xe2x80x98sportsxe2x80x99 web page. This data is processed to obtain rugby display data 120, which is composed of cache pages B1 and B2 and is used to display the xe2x80x98rugbyxe2x80x99 web page on the screen. In the same way, the user then downloads and displays a xe2x80x98NZ All Blacksxe2x80x99 web page represented by all blacks display data 130 composed of cache pages C1, C2 and C3.
Here, cache pages A1, A2, A3, B1, B2, C1, C2 and C3 each represent a portion of a web page. The portions are approximately the same size as the screen.
FIG. 1B is a block diagram of a conventionally managed cache after downloading the data shown in FIG. 1A. The cache 140 stores every cache page of the display data of the downloaded web pages, that is, all of cache pages A1, A2, A3, B1, B2, C1, C2 and C3 shown in FIG. 1A.
FIG. 1C is a block diagram of another example of a conventionally managed cache after downloading the data shown in FIG. 1A. In FIG. 1C, the capacity of the cache 150 is small compared to the amount of downloaded data, thus only the most recent cache pages can be stored. Therefore the cache 150 can store only cache pages B2, C1, C2 and C3, and not A1, A2, A3 and B1.
In the case of FIG. 1C, if the user wants to display the xe2x80x98sportsxe2x80x99 web page again, the user terminal must contact the network and download the required data again, since the cache pages A1, A2 and A3 have disappeared from the cache. Thus, the cache is not always effective in providing faster redisplay. A high percentage of the data stored in the cache is never used. This is because the most useful content of a web page is often at the top of the web page, with less useful content such as advertisements appearing below. Thus, a user often views only the first screen-sized area of the web page, i.e. the portion represented by cache pages A1, B1 or C1. However, all cache pages are stored in the cache. Accordingly, unnecessary data is retained in the cache, wasting the capacity of the cache and lowering the speed for accessing the cache. Thus, the average displaying speed is decreased.
To solve the above problems, it is an object of the present invention to provide a cache management method whereby more useful information can be stored in a cache by storing in the cache only the first cache page of the display data of a web page, thereby increasing cache hit rate and thus rapidly displaying information.
To accomplish the above object, there is provided a method of managing a cache implemented in a user terminal, when a user downloads information from a network to the user terminal, the method comprising the steps of: requesting an item of information through the user terminal by the user; downloading through the network from an external source the item of information requested by the user; and storing in the cache only a first cache page among cache pages which together represent the downloaded item of information.
It is preferable that information is stored in the cache using a FIFO method.
To accomplish another object, there is provided an information downloading method using a cache implemented in a user terminal, comprising the steps of: (a) detecting whether the cache contains a first cache page, among cache pages which together represent an item of information requested by a user; (b) displaying only the information represented by the first cache page, if in step (a) it was detected that the first cache page is stored in the cache; (c) downloading the requested page of information from an external source, if after performing step (b) it is necessary to display more of the requested page of information than the portion represented by the first cache page; and (d) downloading the requested item of information from an external source, and storing in the cache only the first cache page among cache pages which together represent the downloaded item of information, if in step (a) it was detected that the first cache page was not stored in the cache.